How Do Diuretics, or 'Water Pills,' Work?

Question: Two years after my last heart attack, I stated getting short of breath. My doctor gave me lasix. My nurse called it a water pill. What does that mean and how does the medicine work?

Answer: There are a number of medications out there that are called water pills, and what that really means are they're pills that help the body get rid of extra fluid. This can be quite useful for people, say, who had a heart attack, such as yourself; or if the heart muscle is significantly damaged, fluid can build up in the lungs, and if it's really bad, even back up into the legs because the main function of the heart is a pump and if the pump's not working that well, the fluid sort of backs up.

So medicines like Lasix are useful to get that extra fluid out of there. And in a sense, that's why they're called water pills. So it's really getting extra unwanted fluid out of the body. Sometimes medications like Lasix can also be useful for high blood pressure where in some people it's due to extra fluid being on board.